This invention relates generally to a pyrotechnic-based actuator device and, more particularly, to an actuator device for actuating a supply of gas generant material in an inflator device of an inflatable vehicle restraint system.
It is well known to protect a vehicle occupant using a cushion or bag, e.g., an “airbag cushion,” that is inflated or expanded with gas such as when the vehicle encounters sudden deceleration, such as in the event of a collision. In such systems, the airbag cushion is normally housed in an uninflated and folded condition to minimize space requirements. Upon actuation of the system, the cushion begins to be inflated, in a matter of no more than a few milliseconds, with gas produced or supplied by a device commonly referred to as an “inflator.”
Inflators typically include a supply of a gas generant material for producing inflation gas for inflating the airbag cushion. Inflators also typically include an actuator device that actuates, or initiates inflation gas production from, the gas generant material upon receiving an electric signal, such as, for example, from an electrical system for sensing a vehicle crash.
Commonly available actuator devices generally include a chamber for containing a pyrotechnic material. Such actuator device chambers are commonly formed by a cup portion connected to a base portion. An electrical connector, often extending through the base portion, is in initiating combination with the pyrotechnic material. Upon receiving an electric signal through the electrical connector, the pyrotechnic material reacts. Reaction products from the reacting pyrotechnic material rupture the cup portion. A holder element often is disposed around the pyrotechnic material to further hold a consolidated or packed portion of the pyrotechnic material in combination with the electrical connector and to direct the reaction products to rupture the cup portion in an area of an end wall of the cup portion which is opposite the base portion. The end wall of the cup portion is typically perforated or otherwise weakened to facilitate rupturing thereof.
Commonly used pyrotechnic materials are in a dry, powdered form. However, the pyrotechnic materials are often packed into the charge holder in a slurry form and therein allowed to dry. Wetting the powdered pyrotechnic materials to form a slurry decreases the likelihood of unintentional, premature or accidental reaction of the pyrotechnic material, such as, for example, during actuator device manufacture, assembly or installation. Despite being known to be less likely to react prematurely or accidentally, liquid or gel forms of reactive materials, such as are known in the mining industry, are generally not incorporated into commonly used actuator devices. Such liquid-based reactive materials are not generally used in actuator devices for inflatable restraint systems because a portion of the liquid-based reactive material may be expelled from the ruptured end of the actuator device before reacting, thereby resulting in reaction of less than the full amount of reactive material.
There is a need for an actuator device that incorporates additional types or forms, e.g., a liquid, of reactive materials, e.g., pyrotechnic materials.